Hormesis is a term describing the beneficial effects of mild and repeated stimulation or stress, which ultimately bolsters defences against deleterious processes. Although hormetic influences are clearly encountered at the cellular and molecular level, little is known about the effects of hormesis at a clinical level. This paper examines the suggestion that mild stimulation or appropriately timed challenges may be used clinically in order to influence the impact of age-related disease and dysfunction. Examples of stimulation or challenges that may exhibit hormetic effects include dietary restriction, physical and mental exercise, and even social and spiritual stimulation. Dietary restriction places the organism under nutritional stress, stimulating several biochemical repair pathways that may counteract certain age-related changes. Physical and mental challenges, if appropriately timed and sufficiently varied, are directed at increasing the complexity and integration of interacting muscular, cardiovascular, and neural stimuli. Social and spiritual stimulation aimed at reversing age-related loss of dynamical complexity acts upon even higher levels to ensure a reduced risk of social problems in aging.